On Tue, May 5, 2015 at 9:00 PM, Aditya K <hiradi...@msn.com> wrote: > > > ---------------------------------------- >> CC: jwakely....@gmail.com; renato.go...@linaro.org; gcc@gcc.gnu.org >> From: pins...@gmail.com >> Subject: Re: Compiler warnings while compiling gcc with clang >> Date: Tue, 5 May 2015 20:19:04 -0700 >> To: hiradi...@msn.com >> >> >> >> >> >>> On May 5, 2015, at 8:13 PM, Aditya K <hiradi...@msn.com> wrote: >>> >>> So, I analyzed other warnings and following is the list of relevant warning >>> that I could collect. Hope this is useful. >>> >>> >>> gcc/ipa-icf.c:508:12: warning: logical not is only applied to the left hand >>> side of this comparison >>> ../../gcc/ipa-icf.c:508:12: warning: logical not is only applied to the >>> left hand side of this comparison [-Wlogical-not-parentheses] >>> if ((!type == FUNC || address || !opt_for_fn (decl, optimize_size)) >>> >>> gcc/expr.c:5271:9: warning: comparison of constant -1 with expression of >>> type 'unsigned int' is always false >>> [-Wtautological-constant-out-of-range-compare] >>> ../../gcc/expr.c:5271:9: warning: comparison of constant -1 with expression >>> of type 'unsigned int' is always false >>> [-Wtautological-constant-out-of-range-compare] >>> if (!SUBREG_CHECK_PROMOTED_SIGN (target, >>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> >>> There was a similar bug posted some time ago >>> (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61271) >>> -------------------------------------------------------------------------------------------------------------------------------- >>> >>> gcc/reload1.c:470:28: warning: incrementing expression of type bool is >>> deprecated [-Wdeprecated-increment-bool] >>> ../../gcc/reload1.c:470:28: warning: incrementing expression of type bool >>> is deprecated [-Wdeprecated-increment-bool] >>> spill_indirect_levels++; >>> ~~~~~~~~~~~~~~~~~~~~~^ >>> >>> Seems like for this bug we need to change the declaration of >>> >>> bool this_target_reload::x_spill_indirect_levels to an int. Even the >>> comment there mentions that this variable might take >>> other integral values. >>> >>> /* Nonzero if indirect addressing is supported on the machine; this means >>> that spilling (REG n) does not require reloading it into a register in >>> order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The >>> value indicates the level of indirect addressing supported, e.g., two >>> means that (MEM (MEM (REG n))) is also valid if (REG n) does not get >>> a hard register. */ >>> bool x_spill_indirect_levels; >>> >>> >>> -------------------------------------------------------------------------------------------------------------------------------- >>> >>> gcc/rtlanal.c:5573:23: warning: array index 1 is past the end of the array >>> (which contains 1 element) [-Warray-bounds] >>> ../../gcc/rtlanal.c:5573:23: warning: array index 1 is past the end of the >>> array (which contains 1 element) [-Warray-bounds] >>> *second = GEN_INT (CONST_DOUBLE_HIGH (value)); >>> ^~~~~~~~~~~~~~~~~~~~~~~~~ >> >> These warnings are bogus due to the array being the last element of the >> structure. >> >> Please file that with clang. >> > > IIRC, C++ does not allow flexible array members.
But this has been a common extension for many years now (since C++ and C have been around). So warning is useless. Thanks, Andrew > > Thanks, > -Aditya > > >> Thanks, >> Andrew >> >> >> >>> >>> ../../gcc/rtl.h:1757:30: note: expanded from macro 'CONST_DOUBLE_HIGH' >>> #define CONST_DOUBLE_HIGH(r) XCMWINT (r, 1, CONST_DOUBLE, VOIDmode) >>> ^ ~ >>> ../../gcc/rtl.h:1123:36: note: expanded from macro 'XCMWINT' >>> #define XCMWINT(RTX, N, C, M) ((RTX)->u.hwint[N]) >>> ^ >>> ../../gcc/rtl.h:3193:51: note: expanded from macro 'GEN_INT' >>> #define GEN_INT(N) gen_rtx_CONST_INT (VOIDmode, (N)) >>> ^ >>> ../../gcc/rtl.h:397:5: note: array 'hwint' declared here >>> HOST_WIDE_INT hwint[1]; >>> ^ >>> ../../gcc/hwint.h:54:26: note: expanded from macro 'HOST_WIDE_INT' >>> # define HOST_WIDE_INT long >>> ^ >>> >>> -------------------------------------------------------------------------------------------------------------------------------- >>> >>> gcc/vec.h:1048:10: warning: offset of on non-POD type 'vec_embedded' (aka >>> 'vec<c_expr::id_tab, va_heap, vl_embed>') [-Winvalid-offsetof] >>> ../../gcc/vec.h:1048:10: warning: offset of on non-POD type 'vec_embedded' >>> (aka 'vec<std::pair<expr_hash_elt *, expr_hash_elt *>, va_heap, vl_embed>') >>> [-Winvalid-offsetof] >>> return offsetof (vec_embedded, m_vecdata) + alloc * sizeof (T); >>> ^ ~~~~~~~~~ >>> /home/hiraditya/work/llvm/install-release/bin/../lib/clang/3.7.0/include/stddef.h:120:24: >>> note: expanded from macro 'offsetof' >>> #define offsetof(t, d) __builtin_offsetof(t, d) >>> >>> >>> -------------------------------------------------------------------------------------------------------------------------------- >>> >>> genrtl.h:435:3: warning: array index 1 is past the end of the array (which >>> contains 1 element) [-Warray-bounds] >>> ./genrtl.h:435:3: warning: array index 1 is past the end of the array >>> (which contains 1 element) [-Warray-bounds] >>> XWINT (rt, 1) = arg1; >>> ^ ~ >>> ../../gcc/rtl.h:1120:29: note: expanded from macro 'XWINT' >>> #define XWINT(RTX, N) ((RTX)->u.hwint[N]) >>> ^ >>> ../../gcc/rtl.h:397:5: note: array 'hwint' declared here >>> HOST_WIDE_INT hwint[1]; >>> ^ >>> ../../gcc/hwint.h:54:26: note: expanded from macro 'HOST_WIDE_INT' >>> # define HOST_WIDE_INT long >>> >>> -------------------------------------------------------------------------------------------------------------------------------- >>> >>> gcc/final.c:3957:8: warning: array index 1 is past the end of the array >>> (which contains 1 element) [-Warray-bounds] >>> ../../gcc/final.c:3957:8: warning: array index 1 is past the end of the >>> array (which contains 1 element) [-Warray-bounds] >>> if (CONST_DOUBLE_HIGH (x)) >>> ^~~~~~~~~~~~~~~~~~~~~ >>> ../../gcc/rtl.h:1757:30: note: expanded from macro 'CONST_DOUBLE_HIGH' >>> #define CONST_DOUBLE_HIGH(r) XCMWINT (r, 1, CONST_DOUBLE, VOIDmode) >>> ^ ~ >>> ../../gcc/rtl.h:1123:36: note: expanded from macro 'XCMWINT' >>> #define XCMWINT(RTX, N, C, M) ((RTX)->u.hwint[N]) >>> ^ >>> ../../gcc/rtl.h:397:5: note: array 'hwint' declared here >>> HOST_WIDE_INT hwint[1]; >>> ^ >>> ../../gcc/hwint.h:54:26: note: expanded from macro 'HOST_WIDE_INT' >>> # define HOST_WIDE_INT long >>> ^ >>> >>> -------------------------------------------------------------------------------------------------------------------------------- >>> >>> gcc/cse.c:6171:38: warning: array index 1 is past the end of the array >>> (which contains 1 element) [-Warray-bounds] >>> ../../gcc/cse.c:6171:38: warning: array index 1 is past the end of the >>> array (which contains 1 element) [-Warray-bounds] >>> || (CONST_DOUBLE_P (new_rtx) && CONST_DOUBLE_HIGH (new_rtx)>= 0)) >>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> ../../gcc/rtl.h:1757:30: note: expanded from macro 'CONST_DOUBLE_HIGH' >>> #define CONST_DOUBLE_HIGH(r) XCMWINT (r, 1, CONST_DOUBLE, VOIDmode) >>> ^ ~ >>> ../../gcc/rtl.h:1123:36: note: expanded from macro 'XCMWINT' >>> #define XCMWINT(RTX, N, C, M) ((RTX)->u.hwint[N]) >>> ^ >>> ../../gcc/rtl.h:397:5: note: array 'hwint' declared here >>> HOST_WIDE_INT hwint[1]; >>> ^ >>> ../../gcc/hwint.h:54:26: note: expanded from macro 'HOST_WIDE_INT' >>> # define HOST_WIDE_INT long >>> ^ >>> >>> -------------------------------------------------------------------------------------------------------------------------------- >>> >>> gcc/gcov-tool.c:225:7: warning: variable 'ret' is used uninitialized >>> whenever 'if' condition is false [-Wsometimes-uninitialized] >>> gcc/gcov-tool.c:493:7: warning: variable 'ret' is used uninitialized >>> whenever 'if' condition is false [-Wsometimes-uninitialized] >>> ../../gcc/gcov-tool.c:225:7: warning: variable 'ret' is used uninitialized >>> whenever 'if' condition is false [-Wsometimes-uninitialized] >>> if (argc - optind == 2) >>> ^~~~~~~~~~~~~~~~~~ >>> ../../gcc/gcov-tool.c:230:10: note: uninitialized use occurs here >>> return ret; >>> ^~~ >>> ../../gcc/gcov-tool.c:225:3: note: remove the 'if' if its condition is >>> always true >>> if (argc - optind == 2) >>> ^~~~~~~~~~~~~~~~~~~~~~~ >>> ../../gcc/gcov-tool.c:196:10: note: initialize the variable 'ret' to >>> silence this warning >>> int ret; >>> ^ >>> = 0 >>> ../../gcc/gcov-tool.c:493:7: warning: variable 'ret' is used uninitialized >>> whenever 'if' condition is false [-Wsometimes-uninitialized] >>> if (argc - optind == 2) >>> ^~~~~~~~~~~~~~~~~~ >>> ../../gcc/gcov-tool.c:498:10: note: uninitialized use occurs here >>> return ret; >>> ^~~ >>> ../../gcc/gcov-tool.c:493:3: note: remove the 'if' if its condition is >>> always true >>> if (argc - optind == 2) >>> ^~~~~~~~~~~~~~~~~~~~~~~ >>> ../../gcc/gcov-tool.c:462:10: note: initialize the variable 'ret' to >>> silence this warning >>> int ret; >>> ^ >>> = 0 >>> >>> >>> I think I can fix few of these if we want them to be fixed. >>> For some e.g. ( gcc/gcov-tool.c:225:7: warning: array index 1 is past the >>> end of the array (which contains 1 element) ), >>> I have no idea what is the proper fix for them. >>> >>> -Aditya >>> >>> >>>> Date: Tue, 5 May 2015 21:57:08 +0100 >>>> Subject: Re: Compiler warnings while compiling gcc with clang >>>> From: jwakely....@gmail.com >>>> To: hiradi...@msn.com >>>> CC: pins...@gmail.com; renato.go...@linaro.org; gcc@gcc.gnu.org >>>> >>>>> On 5 May 2015 at 12:39, Aditya K wrote: >>>>> There are however, other differences between class and struct >>>>> (http://stackoverflow.com/a/999810/811335) i.e., >>>>> >>>>> 1. In absence of an access-specifier for a base class, public is assumed >>>>> when the derived class is declared struct and private is assumed when the >>>>> class is declared class. >>>> >>>> Yes, everyone here knows that. That is only relevant to the definition >>>> of the class, which can only occur once. For the purposes of >>>> declarations that are not definitions there is no difference. >>>> >>>>> 2. class can be used in place of a typename to declare a template >>>>> parameter, while the struct cannot. >>>> >>>> Completely irrelevant in this context. The use of 'class' in a >>>> template parameter list has nothing to do with struct or class types, >>>> nor forward declarations of struct or class types. >>> >
